1 create tablespace db_name 2 datafile 'D:\oracle\product\10.2.0\oradata\orcl\db_name_.dbf' size 200M 3 autoextend on next 10M maxsize unlimited logging 4 extent management local autoallocate 5 segment space management auto; 解释: 1. 创建
1 create tablespace db_name
2 datafile 'D:\oracle\product\10.2.0\oradata\orcl\db_name_.dbf' size 200M
3 autoextend on next 10M maxsize unlimited logging
4 extent management local autoallocate
5 segment space management auto;
解释:
<span>1. 创建表空间,名称为db_name; 2. 表空间有一个数据文件*.dbf,大小为200MB; 3. 允许表空间自动扩展(autoextends),每次增长10MB(next 10M),并且不限制最大大小; 4. 说明表空间本地(local)管理,并自动分配范围(autoallocate),用户不能指定范围的大小; 5. 段空间(segment)的空间管理上使用bitmaps(auto)来管理数据块。使用AUTO会比使用MANUAL有更好的空间利用率,与效能上的提升。</span>
<p></p><p></p><p><span></span></p><span>Oracle建立表空间和用户 </span><pre class="brush:php;toolbar:false">
<span>建立表空间和用户的步骤: 用户 建立:create user 用户名 identified by "密码"; 授权:grant create session to 用户名; grant create table to 用户名; grant create tablespace to 用户名; grant create view to 用户名;<span> </span> </span><pre class="brush:php;toolbar:false">建立表空间和用户的步骤: 用户 建立:create user 用户名 identified by "密码"; 授权:grant create session to 用户名; grant create table to 用户名; grant create tablespace to 用户名; grant create view to 用户名;
<span>表空间 建立表空间(一般建N个存数据的表空间和一个索引空间): create tablespace 表空间名 datafile ' 路径(要先建好路径)\***.dbf ' size *M tempfile ' 路径\***.dbf ' size *M autoextend on --自动增长 --还有一些定义大小的命令,看需要 default storage( initial 100K, next 100k, );</span>
<span>例子:创建表空间 create tablespace DEMOSPACE datafile 'E:/oracle_tablespaces/DEMOSPACE_TBSPACE.dbf' size 1500M autoextend on next 5M maxsize 3000M; 删除表空间 drop tablespace DEMOSPACE including contents and datafiles</span>
<span>用户权限 授予用户使用表空间的权限: alter user 用户名 quota unlimited on 表空间; 或 alter user 用户名 quota *M on 表空间;</span><p></p><p></p><pre class="brush:php;toolbar:false">用户权限 授予用户使用表空间的权限: alter user 用户名 quota unlimited on 表空间; 或 alter user 用户名 quota *M on 表空间;完整例子:
--1--表空间
CREATE TABLESPACE sdt
DATAFILE 'F:\tablespace\demo' size 800M
EXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO;
--索引表空间
CREATE TABLESPACE sdt_Index
DATAFILE 'F:\tablespace\demo' size 512M
EXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO;
--2.建用户
create user demo identified by demo
default tablespace demo;
--3.赋权
grant connect,resource to demo;
grant create any sequence to demo;
grant create any table to demo;
grant delete any table to demo;
grant insert any table to demo;
grant select any table to demo;
grant unlimited tablespace to demo;
grant execute any procedure to demo;
grant update any table to demo;
grant create any view to demo;
<span>--导入导出命令 ip导出方式: exp demo/demo@127.0.0.1:1521/orcl file=f:/f.dmp full=y exp demo/demo@orcl file=f:/f.dmp full=y imp demo/demo@orcl file=f:/f.dmp full=y ignore=y </span><p></p><p></p><p><span>只导出表结构:</span></p><p><span>PLSQL里</span></p><p><span> tools下</span></p><p><span> export user objects of</span></p><p><span> 按shift批量选择表</span></p><p><span> 执行就行了</span></p> <pre class="brush:php;toolbar:false">

InnoDBBufferPool reduces disk I/O by caching data and indexing pages, improving database performance. Its working principle includes: 1. Data reading: Read data from BufferPool; 2. Data writing: After modifying the data, write to BufferPool and refresh it to disk regularly; 3. Cache management: Use the LRU algorithm to manage cache pages; 4. Reading mechanism: Load adjacent data pages in advance. By sizing the BufferPool and using multiple instances, database performance can be optimized.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

MySQL is worth learning because it is a powerful open source database management system suitable for data storage, management and analysis. 1) MySQL is a relational database that uses SQL to operate data and is suitable for structured data management. 2) The SQL language is the key to interacting with MySQL and supports CRUD operations. 3) The working principle of MySQL includes client/server architecture, storage engine and query optimizer. 4) Basic usage includes creating databases and tables, and advanced usage involves joining tables using JOIN. 5) Common errors include syntax errors and permission issues, and debugging skills include checking syntax and using EXPLAIN commands. 6) Performance optimization involves the use of indexes, optimization of SQL statements and regular maintenance of databases.

MySQL is suitable for beginners to learn database skills. 1. Install MySQL server and client tools. 2. Understand basic SQL queries, such as SELECT. 3. Master data operations: create tables, insert, update, and delete data. 4. Learn advanced skills: subquery and window functions. 5. Debugging and optimization: Check syntax, use indexes, avoid SELECT*, and use LIMIT.

MySQL efficiently manages structured data through table structure and SQL query, and implements inter-table relationships through foreign keys. 1. Define the data format and type when creating a table. 2. Use foreign keys to establish relationships between tables. 3. Improve performance through indexing and query optimization. 4. Regularly backup and monitor databases to ensure data security and performance optimization.

MySQL is an open source relational database management system that is widely used in Web development. Its key features include: 1. Supports multiple storage engines, such as InnoDB and MyISAM, suitable for different scenarios; 2. Provides master-slave replication functions to facilitate load balancing and data backup; 3. Improve query efficiency through query optimization and index use.

SQL is used to interact with MySQL database to realize data addition, deletion, modification, inspection and database design. 1) SQL performs data operations through SELECT, INSERT, UPDATE, DELETE statements; 2) Use CREATE, ALTER, DROP statements for database design and management; 3) Complex queries and data analysis are implemented through SQL to improve business decision-making efficiency.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA


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